Motor

ABSTRACT

A motor for a driving device includes: a rotor rotatable around a central axis, a stator facing the rotor, a busbar electrically connected to the stator, a busbar support to hold the busbar, a terminal bar including a first end electrically connected to the busbar, the terminal bar including a connection terminal at a second end and that is to be electrically connected to the driving device, and a seal to be attached to the driving device and located between the busbar and the connection terminal. The seal portion includes a through-hole into which the terminal bar is press-fitted.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a motor.

2. Description of the Related Art

DE 10 2004 037 639 A1 discloses a motor that includes contact pins thatare integrally connected to a power plug. The contact pins areelectrically connected to a coil of a stator. The contact pins extendstraightly from a position near one end portion of the stator in theaxial direction toward one side in the axial direction.

It is desirable that a liquid, such as oil or water, does not flow intoa plug portion to which a contact pin is connected. If the position ofthe stator is disposed apart from the position of the power plug, it isnecessary to increase the length of the contact pin. If the length ofthe contact pin is increased, the position of the tip of the contact pinbecomes unstable, and it may become difficult to fit the contact pininto the power plug.

SUMMARY OF THE INVENTION

A motor according to an exemplary embodiment of the present disclosure,which is a motor used for a driving device, includes a rotor thatrotates around a central axis; a stator that faces the rotor; a busbarthat is electrically connected to the stator; a busbar support thatholds the busbar; a terminal bar that includes a first end that iselectrically connected to the busbar, the terminal bar including aconnection terminal that is disposed at a second end thereof and that isto be electrically connected to the driving device; and a seal that isto be attached to the driving device and that is disposed between thebusbar and the connection terminal. The seal includes a through-holeinto which the terminal bar is press-fitted.

With the exemplary embodiment of the present disclosure, it is possibleto provide a motor that is used for a driving device and that is able tohermetically seal a terminal portion of the driving device. Moreover,with the exemplary embodiment of the present disclosure, it is possibleto provide a motor that allows a connection terminal of the motor to beeasily attached to the terminal portion of the driving device.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of a motor according to anexemplary embodiment of the present disclosure.

FIG. 2 is a schematic view of a controller of a driving device for whicha motor according to an exemplary embodiment of the present disclosureis used.

FIG. 3 is a schematic side view of a terminal bar of a motor accordingto an exemplary embodiment of the present disclosure.

FIG. 4 is a partial schematic sectional view of a terminal bar of amotor according to an exemplary embodiment of the present disclosure.

FIG. 5 is a schematic perspective view of a busbar support portion of amotor according to an exemplary embodiment of the present disclosure.

FIG. 6 is a schematic perspective view illustrating the relationshipbetween terminal bars and the busbar support portion before the terminalbars are attached to the busbar support portion.

FIG. 7 is a schematic perspective view illustrating the relationshipbetween the terminal bars and the busbar support portion after theterminal bars have been attached to the busbar support portion.

FIG. 8 is a schematic sectional view illustrating a state in which aportion of a terminal bar is inserted into an insertion hole.

FIG. 9 is a schematic sectional view illustrating the relationshipbetween a bar-shaped portion and a tubular portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the drawings. In the presentdescription, the direction in which the central axis A of the motorshown in FIG. 1 extends will be simply referred to as “the axialdirection”, and the radial direction and the circumferential directionthat are centered on the central axis A of the motor will be simplyreferred to as “the radial direction” and “the circumferentialdirection”.

FIG. 1 is a schematic sectional view of a motor 1 according to anembodiment of the present disclosure. The motor 1 is used for a drivingdevice. In the present embodiment, the driving device is an electricbraking device, and the motor 1 is a brushless motor. However, a drivingdevice for which a motor according to the present disclosure is used isnot limited to an electric braking device. For example, a driving devicefor which a motor according to the present disclosure is used may be anelectric power steering device or the like.

The motor 1 includes a rotor 10 that rotates around the central axis A.The rotor 10 includes a hollow shaft 11 that extends along the centralaxis A. To be specific, the hollow shaft has a structure such that twocylindrical portions having different outside diameters are arranged inthe axial direction. Compared with the outside diameter of an endportion of the hollow shaft 11 on one side in the axial direction, theoutside diameter of an end portion of the hollow shaft 11 on the otherside in the axial direction is small. A cylindrical portion 11 a, whichis included in the end portion on the other side in the axial direction,is rotatably supported by a bearing 13 of the motor 1. The rotor 10includes a magnet 12 that is disposed outside of the hollow shaft 11 inthe radial direction. For example, the magnet 12 is fixed to the hollowshaft 11 by using a cover (not shown) that is disposed outside of themagnet 12 in the radial direction.

The motor 1 includes a stator 20 that faces the rotor 10. The stator 20includes a stator core 21, an insulator 22, and a coil 23. The statorcore 21 is formed by stacking a plurality of magnetic steel sheets inthe axial direction. However, this is an example. For example, thestator core 21 may be formed of one member or may be formed by combininga plurality of members. An inner peripheral surface of the stator core21 faces an outer peripheral surface of the rotor 10. The stator core 21includes a core back 211, which has an annular shape, and teeth 212,which protrude from the core back 211 inward in the radial direction.The teeth 212 are arranged at regular intervals in the circumferentialdirection. The teeth 212 are covered by the insulator 22. For example,the insulator 22 is an insulating member such as a resin member. Thecoil 23 is formed by winding a conductor wire around each of the teeth212 via the insulator 22.

The motor 1 includes a busbar 30, which is electrically connected to thestator 20, and a busbar support portion 40, which holds the busbar 30.The busbar support portion 40 is disposed so as to face an end portionof the stator 20 on one side in the axial direction. A lead wireextending from the coil 23 is electrically connected to the busbar 30,which is held by the busbar support portion 40. Details of the busbar 30and the busbar support portion 40 will be described below.

The motor 1 includes a terminal bar 50 that has a first end portion E1that is electrically connected to the busbar 30. The terminal bar 50includes a connection terminal 51 that is disposed at a second endportion E2 thereof and that is to be electrically connected to thedriving device. In the present embodiment, the terminal bar 50 extendstoward one side in the axial direction. In the present embodiment, thefirst end portion E1 is an end portion on the other side in the axialdirection, and the second end portion E2 is an end portion on the oneside in the axial direction. The connection terminal 51 is aplate-shaped member made of a metal such as copper. Details of theterminal bar 50 will be described below.

FIG. 2 is a schematic view of a controller 101 of a driving device 100for which the motor 1 according to the embodiment of the presentdisclosure is used. The controller 101 controls driving of the motor 1.In the present embodiment, the controller 101 is disposed so as to beseparated from the motor 1 toward one side in the axial direction. Thecontroller 101 has insertion holes 101 a, in which terminal portions 101b are disposed. The controller 101 is disposed in an orientation suchthat the insertion holes 101 a face the motor 1. The insertion holes 101a extend in the axial direction. The connection terminals 51 areinserted into the insertion holes 101 a and are connected to theterminal portions 101 b, which are disposed in the insertion holes 101a. Thus, electric power is supplied to the coil 23 from the controller101 via the terminal bars 50 and the busbars 30.

The motor 1 includes a housing 60, which extends in the axial directionand which has a substantially cylindrical shape having a bottom. Abottom wall 60 a of the housing 60 is positioned on the other side inthe axial direction. The housing 60 is disposed outside of the stator 20in the radial direction and surrounds the stator 20. The bearing 13 isfixed to a central portion of the housing 60 on the bottom wall side.

The motor 1 drives a piston mechanism 102 of the driving device 100. Thepiston mechanism 102 includes a ball screw, a piston, and a cylinder,which are not shown in the figures. When the motor 1 is driven, thehollow shaft 11 rotates. When the hollow shaft 11 rotates, the ballscrew is driven, and the position of the piston in the cylinder variesin the axial direction. When the piston is driven, a braking pressurevaries.

FIG. 3 is a schematic side view of the terminal bar 50 of the motor 1according to the embodiment of the present disclosure. The terminal bar50 includes, in addition to the connection terminal 51, a bar-shapedportion 52 and a mold portion 53. The bar-shaped portion 52 is locatedbetween the busbar 30 and the connection terminal 51. The bar-shapedportion 52 is a round bar made of a metal such as copper. The moldportion 53 covers a part of the bar-shaped portion 52 and a part theconnection terminal 51 while electrically connecting the bar-shapedportion 52 and the connection terminal 51 to each other. The moldportion 53 is made of an insulating resin.

FIG. 4 is a partial schematic sectional view of the terminal bar 50 ofthe motor 1 according to the embodiment of the present disclosure. Asillustrated in FIG. 4, one end portion of the connection terminal 51 andone end portion of the bar-shaped portion 52 overlap, and the connectionterminal 51 and the bar-shaped portion 52 are connected to each other.In the present embodiment, a flat portion 52 a is formed at the one endportion of the bar-shaped portion 52. This makes it easier to connectthe connection terminal 51 to the bar-shaped portion 52.

The mold portion 53 covers a part of the connection terminal 51 and apart of the bar-shaped portion 52, the parts including connectionportions where the connection terminal 51 and the bar-shaped portion 52are connected to each other. Thus, the connection terminal 51 and thebar-shaped portion 52 are fixed to each other in a connected state, andthe connection terminal 51 and the bar-shaped portion 52 areelectrically connected to each other. In the present embodiment, themold portion 53 has a substantially cylindrical shape. To be morespecific, the outside diameter of an end portion of the mold portion 53on the bar-shaped portion 52 side is larger than the outside diameter ofan end portion of the mold portion 53 on the connection terminal 51side. Thus, the contact area of an end surface of the mold portion 53 onthe bar-shaped portion 52 side can be increased.

The motor 1 includes a seal portion 54 that is disposed between thebusbar 30 and the connection terminal 51. The seal portion 54 is to beattached to the driving device 100. In the present embodiment, the sealportion 54 is to be attached to the controller 101 of the driving device100. The relationship between the seal portion 54 and the controller 101will be described below.

The seal portion 54 is made of an elastic material such as rubber. Theseal portion 54 has a through-hole 54 a into which the terminal bar 50is press-fitted. To be specific, the diameter of the through-hole 54 ais smaller than the diameter of the bar-shaped portion 52. Thebar-shaped portion 52 is press-fitted into the through-hole 54 a. Thatis, the seal portion 54 is attached to the bar-shaped portion 52. To bemore specific, the seal portion 54 is in contact with the end portion ofthe mold portion 53 on the bar-shaped portion 52 side. With thisstructure, the position of the seal portion 54, into which thebar-shaped portion 52 is press-fitted, can be determined by using themold portion 53, and manufacturing of the terminal bar 50 can befacilitated.

The seal portion 54 includes at least one protruding portion 54 b thatextends one turn along an outer peripheral surface of the seal portion54. In other words, the seal portion 54 includes at least one protrudingportion 54 b that is ring-shaped. In the present embodiment, the sealportion 54 includes three protruding portions 54 b. The three protrudingportions 54 b are disposed with spaces therebetween. By forming theprotruding portions 54 b, workability when inserting the terminal bar 50into the insertion hole 101 a can be improved, and the seal portion 54can closely contact an inner wall of the insertion hole 101 a.Preferably, the seal portion 54 includes a plurality of the protrudingportions 54 b in order that the seal portion 54 can closely contact theinner wall of the insertion hole 101 a.

FIG. 5 is a schematic perspective view of the busbar support portion 40of the motor 1 according to the embodiment of the present disclosure. Asillustrated in FIG. 5, the busbar support portion 40 includes tubularportions 41 and a holding portion 42. In the present embodiment, thetubular portions 41 and the holding portion 42 are integrally formed.The busbar support portion 40 is made of an insulating resin.

The bar-shaped portion 52 is inserted into each of the tubular portions41. In the present embodiment, the tubular portions 41 each have acylindrical shape. The busbar support portion 40 includes the pluralityof tubular portions 41. In the present embodiment, the motor 1 has thecoil 23 having three phases, which are the U-phase, the V-phase, and theW-phase. Therefore, the controller 101 includes three terminal portions101 b, and the motor 1 includes three terminal bars 50. Because thereare three terminal bars 50, the busbar support portion 40 includes threetubular portions 41, which are arranged in the circumferentialdirection. Each of the tubular portions 41 extends toward one side inthe axial direction. The tubular portion 41 can stabilize the positionof the terminal bar 50, which extends toward the one side in the axialdirection.

The holding portion 42 holds the busbar 30. The tubular portion 41protrudes from the holding portion 42. In the present embodiment, theholding portion 42 has an annular shape. The tubular portion 41protrudes from the holding portion 42 toward one side in the axialdirection. The holding portion 42 is integrated with the busbar 30 byinsertion molding. The busbar 30 includes a hook portion 31 thatprotrudes from an outer peripheral surface of the holding portion 42. Alead wire (not shown), which extends from the coil 23, is attached tothe hook portion 31. The lead wire and the busbar 30 are electricallyconnected to each other. The number of hook portions 31 may be changedas appropriate in accordance with the wiring structure of the coil 23.

In the present embodiment, the busbar 30 includes four types of busbars,which are a busbar for the U-phase, a busbar for the V-phase, a busbarfor the W-phase, and a busbar for the neutral point. However, this is anexample, and, if the coil 23 is formed by delta connection instead ofstar connection, the busbar for the neutral point may be omitted. Theplurality of types of busbars are structured so that a busbar of onetype do not contact a busbar of any other type. For example, the heightpositions of the busbars are changed in accordance with the types.

The holding portion 42 includes an L-shaped leg portion 43 thatprotrudes outward in the radial direction from an annular body portionthereof. The leg portion 43 determines the height of the busbar supportportion 40 relative to the stator 20 in the axial direction. In thepresent embodiment, the holding portion 42 includes three leg portions43. The three leg portions 43 are arranged at substantially regularintervals in the circumferential direction. To be specific, the threeleg portions 43 include two first leg portions 431, which have the sameshape, and a second leg portion 432, whose width in the circumferentialdirection is larger than that of each of the first leg portions 431. Thethree tubular portions 41 are disposed on the second leg portion 432.

As illustrated in FIG. 5, each of the tubular portions 41 includes a rib41 a on an outer surface thereof. The rib 41 a extends in the axialdirection. In the present embodiment, the rib 41 a is a plate-shapedmember having a trapezoidal shape. The rib 41 a extends in the axialdirection from an end portion of the tubular portion 41 on the secondleg portion 432 side to a central portion of the tubular portion 41. Therib 41 a protrudes from the tubular portion 41 inward in the radialdirection. The width of an end portion of the rib 41 a on the second legportion 432 side in the axial direction is larger than the width of anend portion of the rib 41 a on the opposite side. Preferably, the rib 41a and the tubular portion 41 are integrally formed. The rib 41 a canincrease the strength of the tubular portion 41 and stabilize theposition of the tubular portion 41.

As illustrated in FIG. 5, each adjacent pair of the plurality of tubularportions 41 are coupled to each other by a coupling piece 44. In thepresent embodiment, the coupling piece 44 has a rectangular plate-likeshape, and the number of coupling pieces 44 is two. The coupling piece44 extends in the axial direction from an end portion of the tubularportion 41 on the second leg portion 432 side to a central portion ofthe tubular portion 41. Preferably, the coupling piece 44 and thetubular portion 41 are integrally formed. The coupling pieces 44 canincrease the strength of the plurality of tubular portions 41 and cankeep the positional relationship between the plurality of tubularportions 41.

FIG. 6 is a schematic perspective view illustrating the relationshipbetween the terminal bars 50 and the busbar support portion 40 beforethe terminal bars 50 are attached to the busbar support portion 40. FIG.7 is a schematic perspective view illustrating the relationship betweenthe terminal bars 50 and the busbar support portion 40 after theterminal bars 50 have been attached to the busbar support portion 40.FIG. 7 illustrates a part of the busbar support portion 40 and parts theterminal bars 50.

As illustrated in FIG. 6, the three terminal bars 50 are each insertedinto a corresponding one of the tubular portions 41 from an end portionthereof on a side opposite to the connection terminal 51 side. Thebar-shaped portion 52 of each of the terminal bars 50 is inserted into acorresponding one of the tubular portions 41. As illustrated in FIG. 7,the busbars 30 are electrically connected to the bar-shaped portions 52on the base side of the tubular portions 41. Because the busbars 30 areheld by the holding portion 42, connection portions can be easilydisposed on the base side of the tubular portions 41. Therefore, withthe structure of the present embodiment, it is easy to electricallyconnect the busbars 30 and the terminal bars 50 to each other.

In the present embodiment, a connection portion 32 of each of thebusbars 30 is disposed on the second leg portion 432. The connectionportion 32 is a part of the busbar 30 that protrudes from the annularbody portion of the holding portion 42 outward in the radial direction.To be specific, on the second leg portion 432, three connection portions32, which are a connection portion for the U-phase, a connection portionfor the V-phase, and a connection portion for the W-phase, are disposed.The connection portions 32 are disposed on the base side of the tubularportions 41 at positions that are arranged adjacent to the tubularportions 41 in the axial direction. Each of the connection portions 32has a cylindrical shape. As illustrated in FIG. 7, end portions of thebar-shaped portions 52, which are inserted into the tubular portions 41,are inserted into the connection portions 32. The bar-shaped portions52, which are inserted into the connection portions 32, are electricallyconnected to the busbars 30 by, for example, being welded.

With the structure of the present embodiment, end portions of theterminal bars 50 can be guided to the connection portions 32 whiledetermining the positions of the terminal bars 50 by using the tubularportions 41. Therefore, the terminal bars 50 and the busbars 30 can beelectrically connected to each other easily. Moreover, because thedirection in which the terminal bars 50 extend is guided by the tubularportions 41, the positions of the terminal bars 50, including thepositions of the connection terminals 51 on the tip end side, can bestabilized. The structure according to the present embodiment isparticularly effective in a case where the distance between the motor 1and the controller 101 is large and the length of the terminal bar 50 islarge.

FIG. 8 is a schematic sectional view illustrating a state in which apart of the terminal bar 50 is inserted into the insertion hole 101 a.In order to connect the terminal portion 101 b (see FIG. 2) and theconnection terminal 51, a part of the terminal bar 50 on the connectionterminal 51 side is inserted into the insertion hole 101 a. Thus, theseal portion 54, which is attached to the terminal bar 50, is attachedto an inner wall of the insertion hole 101 a. The seal portion 54closely contacts the bar-shaped portion 52 and the inner wall of theinsertion hole 101 a. Therefore, the terminal portion 101 b ishermetically sealed by the seal portion 54. That is, a liquid, such asoil or water, can be prevented from flowing into the terminal portion101 b.

To be specific, the inside diameter R1 of the insertion hole 101 a islarger than the maximum outside diameter R2 of the mold portion 53. Theinside diameter R1 of the insertion hole 101 a is smaller than theoutside diameter R3 (see FIG. 4) of a part of the seal portion 54 onwhich the protruding portion 54 b is formed. The inside diameter R1 ofthe insertion hole 101 a is larger than the outside diameter R4 (seeFIG. 4) of a part of the seal portion 54 on which the protruding portion54 b is not formed.

Due to the relationship R1>R2, a tip end portion of the terminal bar 50,including the mold portion 53, can be easily inserted into the insertionhole 101 a. Due to the relationships R1<R3 and R1>R4, the seal portion54 is inserted into the insertion hole 101 a while the protrudingportion 54 b is being compressed. Because the protruding portion 54 b iscompressed, the seal portion 54 comes into close contact with the innerwall of the insertion hole 101 a. Moreover, the bar-shaped portion 52has been press-fitted into the through-hole 54 a of the seal portion 54.Therefore, the seal portion 54 hermetically seals the terminal portion101 b; and a liquid, such as oil or water, can be prevented from flowinginto the terminal portion 101 b. The protruding portion 54 b may beomitted. However, in this case, in order to make the seal portion 54closely contact the inner wall of the insertion hole 101 a, workabilityof the operation of inserting the seal portion 54 into the insertionhole 101 a decreases. Therefore, preferably, the seal portion 54 has theprotruding portion 54 b.

FIG. 9 is a schematic sectional view illustrating the relationshipbetween the bar-shaped portion 52 and the tubular portion 41. Asillustrated in FIG. 9, a gap S is formed between the tubular portion 41and the bar-shaped portion 52, which is inserted into the tubularportion 41. In the present embodiment, the outside diameter of thebar-shaped portion 52 is smaller than the inside diameter of the tubularportion 41. Therefore, the gap S is formed. Because the gap S is formed,the terminal bar 50 can move in an in-plane direction that isperpendicular to the axial direction. Thus, it is possible to connectthe connection terminal 51 to the terminal portion 101 b while adjustingthe position of the terminal bar 50, and it is possible to easily attachthe connection terminal 51 to the terminal portion 101 b. The structureof the present embodiment is particularly effective in a case where thedistance between the motor 1 and the controller 101 is large and thelength of the terminal bar 50 is large.

The structure of the embodiment described above is only an example ofthe present disclosure. The structure of the embodiment may be modifiedas appropriate within the technical scope of the present disclosure. Theembodiment and minor modifications of the embodiment may be used incombination where feasible.

In the structure described above, the terminal bar 50 extends in theaxial direction. However, this is only an example. For example, theterminal bar 50 may extend in the radial direction. In this case, thetubular portion 41 may also extend in the radial direction instead ofthe axial direction.

The present disclosure is widely applicable to a motor that is used, forexample, for household electrical appliances, automobiles, ships,aircrafts, and trains.

Features of the above-described preferred embodiments and themodifications thereof may be combined appropriately as long as noconflict arises.

While preferred embodiments of the present disclosure have beendescribed above, it is to be understood that variations andmodifications will be apparent to those skilled in the art withoutdeparting from the scope and spirit of the present disclosure. The scopeof the present disclosure, therefore, is to be determined solely by thefollowing claims.

The invention claimed is:
 1. A motor used for a driving device, themotor comprising: a rotor that rotates around a central axis; a statorthat faces the rotor; a busbar that is electrically connected to thestator; a busbar support that holds the busbar; a terminal bar includinga first end electrically connected to the busbar, the terminal barincluding a connection terminal at a second end thereof and to beelectrically connected to the driving device; and a seal to be attachedto the driving device and located between the busbar and the connectionterminal; wherein the seal includes a through-hole into which theterminal bar is press-fitted.
 2. The motor according to claim 1, whereinthe terminal bar further includes: a bar-shaped portion located betweenthe busbar and the connection terminal; and a mold portion that covers aportion of the bar-shaped portion and a portion of the connectionterminal while electrically connecting the bar-shaped portion and theconnection terminal to each other; wherein the seal is in contact withan end of the mold portion on a side of the bar-shaped portion.
 3. Themotor according to claim 1, wherein the seal includes at least oneprotrusion extending one turn along an outer peripheral surface of theseal.
 4. The motor according to claim 2, wherein the busbar supportincludes a tubular portion into which the bar-shaped portion isinserted.
 5. The motor according to claim 4, wherein a gap is locatedbetween the tubular portion and the bar-shaped portion.
 6. The motoraccording to claim 4, wherein the busbar support faces an end of thestator on one side in an axial direction, and the tubular portionextends toward the one side in the axial direction.
 7. The motoraccording to claim 4, wherein the tubular portion includes a rib on anouter surface thereof, the rib extending in an axial direction.
 8. Themotor according to claim 4, wherein the busbar support includes aplurality of the tubular portions; and each adjacent pair of theplurality of tubular portions are coupled to each other by a coupler. 9.The motor according to claim 4, wherein the busbar support furtherincludes a holder that holds the busbar; the tubular portion protrudesfrom the holder; and the busbar is electrically connected to thebar-shaped portion at a position on a base side of the tubular portion.